Serve Preview

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description must carry the whole behavioral burden. It does disclose two real traits: binding is localhost-only and hidden files are blocked. But it says nothing about server lifecycle — whether 'start' launches a persistent background process, what it returns (a URL/port?), whether repeated starts stack, or how 'stop' identifies which server to stop when no port is supplied.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the core capability and followed by the two constraints that matter most. No filler, no restatement of the title, and the security warning lands where a reader will actually see it.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool that starts and stops a server process, the missing pieces are lifecycle and return information: does start yield a URL the agent can hand to a user, and is the server persistent across later calls? With no annotations and no output schema, the description is the only place those could be stated, and they aren't. Adequate for the happy path, incomplete for an agent managing a running process.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, with per-parameter descriptions already covering the port fallback behavior, the root default of '.', and the action default of 'start'. The description adds no parameter-level detail beyond that, so the baseline 3 applies rather than a higher score.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a precise verb pair ('start or stop') and a precisely scoped resource ('localhost-only static preview for HTML, CSS, JS, and SVG'). The 'Not a deployment service' line pre-empts the most likely misreading, though no sibling is named — the other tools in the set (icons, design tokens, screenshots) are far enough away that explicit differentiation isn't critical.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives clear context for when this applies (local static preview of web assets) and an explicit exclusion via 'Not a deployment service'. It also warns against serving files with secrets, which is a use-time constraint. It stops short of naming an alternative tool for handoff/deployment scenarios, which the sibling list suggests exists (prepare_web_handoff).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.